2009 Iowa Code
Title 8 - Transportation
Subtitle 1 - Highways and Waterways
CHAPTER 314 - ADMINISTRATIVE PROVISIONS FOR HIGHWAYS
314.24 - NATURAL AND HISTORIC PRESERVATION.

        314.24  NATURAL AND HISTORIC PRESERVATION.
         Cities, counties, and the department shall to the extent
      practicable preserve and protect the natural and historic heritage of
      the state in the design, construction, reconstruction, relocation,
      repair, or maintenance of roads, streets, or highways.  Destruction
      or damage to natural areas, including but not limited to prime
      agricultural land, parks, preserves, woodlands, wetlands, recreation
      areas, greenbelts, historical sites, or archaeological sites shall be
      avoided, if reasonable alternatives are available for the location of
      roads, streets, or highways at no significantly greater cost.  In
      implementing this section, cities, counties, and the department shall
      make a diligent effort to identify and examine the comparative cost
      of utilizing alternative locations for roads, streets, or highways.
      

         89 Acts, ch 317, §30